The C-2001 regulator is an LPG liquid withdrawal high pressure regulator. This regulator provides excellent fuel delivery with liquid-cooled engines. With the C-2001's improved vaporization characteristics, liquid propane enters the regulator and then is vaporized using heat from the engine's coolant. LP-Gas is fed to the underside of the diaphragm through a small orifice. A pilot valve moves a lever in the regulator and a larger orifice is opened up and pressure under the diaphragm is lowered. This pressure differential allows the diaphragm to push the main valve to open as long as the engine vacuum maintains the pilot valve pin in the open position. The instant the engine stops the pilot valve is closed (spring assisted) stopping fuel flow. This is the unique lockoff feature of the C-2001 regulator.